TENDRILS 



tangled together that it is quite impossible even to cut into 

 them, and they are practically impenetrable. 



Some of our common British twiners climb very quickly. 

 A complete turn round the supporting pole was made in 

 England, at Charles Darwin's home, in the following times. 

 The Hop took 2 hrs. 8 mins., Wistaria 2 hrs. 5 mins., Con- 

 vohoilus 1 hr. 42 mins., and Phaseolus 1 hr. 54 mins. A 

 Honeysuckle took 7 hrs. 30 mins. to make one complete turn 

 round the support. 



Recently Miss Elizabeth A. Simons timed the rate of 

 growth of the same plants at the University of Pennsylvania. 

 They seem to have been stimulated by the exhilarating 

 atmosphere of the United States, for they were all growing 

 faster. The Hop did its turn in 1 hr. 5 mins., Phaseolus 

 took from 1 hr. to 1 hr. 20 mins., Convolvulus 57 mins. 

 only, Lonicera from 1 hr. 43 mins. to 2 hrs. 48 mins., and 

 Wistaria 2 hrs.^ But there are curious variations in the 

 rate at which these plants revolve. 



Thus when coming towards the light they go as fast as 

 they can, but revolve more slowly, and as it were reluc- 

 tantly, away from it. It has been found in one case that 

 the shoot took thirty-five minutes to do the semicircle 

 towards the light, and an hour and fifteen to twenty minutes 

 going away from it, but this is not always the case, for 

 sometimes the reverse takes place - (Baranetzki). 



These twining plants are not very common in Great 

 Britain, and indeed in Europe. Some of them move or 

 twine to the right (in the same direction as the hands of 

 a watch or of the sun), such as Convolvulus (Bindweed), 

 Phaseolus, Ipomcea, and Aristolochia. Others, like the Hop, 



1 Trans, and Proc. Bot. Soc. Pennsylvania, Session 1397-8, vol. 1, No. 1. 

 ' Pfeffer, Pjlanzen-Physiologie, voi. -2, p. ^12. 



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